The invention relates to a template for an eyeglass lens with at least one hole or one marking.
Templates for eyeglass lenses serve, among other things, to determine the locations at which holes are to be drilled through the eyeglass lens or to determine the position at which a fitting or mounting is to be affixed, for example by gluing. Using a template, markings can also be applied to an eyeglass lens. Templates are also particularly necessary when ear pieces (cheek pieces) or nose bridges for frameless eyeglasses must be affixed to the eyeglass lenses.
Various templates are already known: The subject of published German patent application 44 38 634 is a template with which the location can be determined at which a bore hole is to be drilled in an eyeglass lens. This template can be a transparent sheet which can be laid on the eyeglass lens on top of an adhesive surface. The adhesive effect is designed such that on the one hand, a slipping of the sheet on the glass is not possible during the operative procedures; on the other hand, the sheet can be removed without difficulty from the glass after being worked on.
This type of template is difficult to deal with since laying a flat adhesive sheet onto a curved eyeglass lens surface generally isn't successful on the first try. Since the sheet sticks, it cannot be slid or turned with respect to the glass. Rather, it must be completely removed from the glass. Moreover, a sheet is not very suitable as a bore template. On the one hand, it is difficult to drill bore holes which are to be an exact distance from one another. On the other hand, it is difficult to drill a hole in the glass such that the bore hole axis is at a desired angle to the surrounding glass surface.
From the German utility model 93 04 045 it is known to also use as a hole gauge an eyeglass lens former which is used to grind eyeglass lenses. For this purpose, holes are located in the eyeglass lens former. For drilling, an eyeglass lens former is placed on the eyeglass lens. The holes in the eyeglass lens former are used as a guide for a drill. The eyeglass lens former is a rigid, flat disc. In order to be able to drill perfectly, it is necessary to use a plate with pins for receiving an eyeglass lens former and also with additional eccentric stops. In this way the eyeglass lens and eyeglass lens former can be adjusted to one another, however the use of this template is very expensive. The lens and the eyeglass lens former are attached to each other with an adhesive pad.
Using rigid, flat templates with openings for a drill is also known. The templates are placed tangentially in the central region of an eyeglass lens. If bore holes in the outer region of the lens are made into it, the axes of the bore holes form differing angles with respect to the surface of the eyeglass lens, which angles depend on the curvature of the surface of the eyeglass lens. This can be disadvantageous for affixing fittings.